constable



J. L. CONSTABLE.

Shaft Furnace. N0;39. 257. Patented July 14. 1863- In w't nes ses i WfiwAM. PHOTO-LITHOJQ NM (OSBORNE'S PROCESS) JOHN L. CONSTABLE,

OF NEXV YORK, N. Y.

IMPROVEMENT lN REFINING ORES.

Specification forming part of Letters Patent No. 39,257, dated July 14,1863.

generally accompany the gold are, chiefly, iron pyrites, copper pyrites,and mispickel or arsenical pyrites, and it is this combination withsulphur in some shape or other, whether it is chemical or merelymechanical, that prevents the dissolution of all the gold in the ore byamalgamation with mercury. I11 auriferous pyrites, which are alsoferruginous, the gold may be invisible when it is first mined, althoughit may be present in an appreciable quantity; but by subsequent exposureto moisture or the action of the atmosphere, which occasions itsdecomposition, the metallic gold becomes apparent in bright particles,shining on the reddish bottom of the oxidized iron 5 and this takesplace by the absorption of the sulphur by the iron, on account of theirincreased affinity under the change of circum-. stances, releasing aportion of the gold which may have otherwise remained hidden andinseparable under the form of an intractable sulphuret. "Where there isnot sufficient iron to take up all the sulphur, or where there is noiron at all in the ore, the sulphur prevents the amalgamation of thegold and its recovery from the ore in all those cases where mercuryalone has been depended upon to effect the separation and reduction ofthe gold. In a similar manner the variety of auriferous pyrites, whichis found in argillaceous loam, and is called greasy quartz, andisaccompanied with the debris of rocks, is sometimes unprofitable to work,on account of the same difficulty which has hitherto existed ofdesulphurizing the ore, and removing from it the other volatileimpurities which prevent its combination with mercury.

The object of my invention is to remove this sulphur and otherobjectionable matter from the ore; and it is accomplished by subjectingthe ore, in a comminut-ed state, to the action of a blast of combinedhot air and superheated steam in such a manner that every atom of thefinely-divided auriferous matter will be enveloped and brought incontact with the steam and gaseous results of combustion heated abovethe volatilizing temperature of sulphur to about 800.

The preceding remarks have been principally directed to the ores ofgold; but it is obvious that the same treatment may be usefully appliedto the ores of silver, and nickel, and other ores which are combinedwith sulphur and other volatile matter; and it is believed that the useof a superheated-steam blast, in

combination with a furnace, may be made to develop a degree of heat ofsufficient intensity to burn the iron out of gold and other valuableores where it may be necessary and desirable to calcine them withoutdirect contact with a furnace.

To enable others skilled in the arts to which it appertains to make anduse my invention, I will proceed to describe its construction andoperation with reference to the drawing.

The pipe a proceeds from an ordinary steamboiler, b, and traverses thefurnace c in a series of coils, d, by which the steam passing through itbecomes highly superheated. The steam is delivered after the manner of ablast into the fine 0 of the furnace in the vicinity of a hopper, f,which also discharges into the flue. The crushed and ground ore isplaced in the hopper, from which it falls into the flue, where it iscaught in the current of hot air and superheated steam, and carriedeither into the open air or into a chamber, as hereinafter described.The steam-pipe and the hopper are furnished with valves for the purposeof controlling the flow of the steam and the ore in the ordinary manner,as they would be applied for analogous purposes by an ordinary mechanic.

XVhen the particles of metal under treatment are very minute, as isoften the case with gold, if the blast were delivered into the open air,it would involve considerable loss, and it is therefore sometimesdesirable to deliver it into a close chamber, 9, where the heavierparticles will fall upon the floor, and the lighter ones will beretained upon the wetted gauze, which covers the disk of the revolvingwheel h in the passage of the blast through the meshes of the gauze inmaking its exit through the flue i to the chimney. The lower portion ofthe wheel h dips into the tank of water 75, and the part opposite theflue may be constantly kept wet, when the apparatus is in use, by slowlyrevolving the Wheel by means of the pulley Z 011 the outer end of theshaft on which it is placed.

The advantages of the apparatus I have described and illustratedconsist, chiefly, in using a blast of superheated steam to impel thecombustion of the furnace, and in employing this blast, together withthe products of combustion which have been thus intensified, for thepurpose of refinin g ore sand impure metals; and I make no claim,therefore, to the principle of pose specified.

JOHN L. CONSTABLE. lVitnesses: 1

I. BURNHAM, WM. Kmrnnn Hunt.

